Ischemia is a decrease in the blood supply to a body organ, tissue or part caused by constriction or obstruction of the blood vessels. Ischemia is often linked to coronary artery disease, cardiovascular events, angina, headaches or other vascular symptoms.
Myocardial ischemia is a particularly prevalent problem for menopausal females. Estradiol 17.beta. (E2) has anti-ischemic properties and has been suggested for primary and secondary prevention of coronary artery disease in menopausal females. However, a large proportion of menopausal women need adjunctive therapy with progestins, which include progesterone and the synthetic progestins, in order to reduce the occurrence of uterine malignancy. The synthetic progestins, unlike progesterone, normally can be effectively administered orally, and so have been the predominant choice over progesterone itself, which is minimally active when administered orally. One major problem with co-treatment using synthetic progestins, however, is that synthetic progestins, such as medroxyprogesterone acetate (MPA), tend to reverse some or all of the beneficial effects of estrogen on myocardial ischemia. Use of progestins in women with cardiovascular problems has often been avoided due to negative effects associated with these drugs. MPA is one of the most prescribed and tested progestins in hormone replacement therapy.
Use of a progestin in hormone replacement therapy that actually supplements, rather than adversely interferes with, estrogen replacement therapy for women with ischemia is therefore of particular interest. Unlike synthetic progestins, administration of progesterone itself provides this unexpected benefit.